Sahih Muslim Book 21, Hadith Number 4760.

Chapter : It is permissible to eat the animals of water even if they are dead.

Jabir b. ‘Abdullah reported that Allah’s Messenger (may peace be upon him) sent on in expedition a detachment consisting of three hundred (persons) and appointed Abu ‘Ubaida b. Jarrah as their chief. Their provisions ran short: ‘Abu ‘Ubaida collected their provisions in the provision bag and he fed us (for some time). Later on when the provisions ran short he gave us one date every day.